Toyota Detonating

If it's relatively drivable, I'd run out the tank and try some Techron, or fuel containing same (Chevron? Shell?).

Are you sure it was detonating, or was it simply bucking and losing power. If it's the latter, you may have simply picked up a bad load of gas and clogged the fuel filter.

Or that it has lost its tolerance for 87 octane fuel whch is realy too low to begin with for most modern engines. Octane requirement is not constant and it increases with tempature and load. You might check to see if it has a kcock sensor that has failed (a lot of vehicle have one and retard spark (and performance and MPG too) when it hears a knock before you hear it

----------------- The SnoMan

Thanks for the input Dwight . It is definitly detonating, sounds awful. I am going to run this tank out and try some different fuel. It has just turned hot here in Phoenix (over 100) but the truck has always lived here and has never done this before. I did some checking and found the knock sensors are under the intake manifold , the dealer says if they were bad the check engine light would be on. When I put the different fuel in I will report on what takes place. Scott

Even if it's detonating, he could have picked up a bad load of fuel.

You can also try octane booster. Or, let the tank drop to about the half way mark, and top it off with premium, then go back to the regular when that is gone.

Cheaper to use better gas than octane booster

----------------- The SnoMan

In the long run, that is definitely true.

But, he bought a load of crappy gas and needs to recover. Obviously, he thought he was buying good gas -- he went to Costco -- but you need to understand he is in Arizona, and they can get gas from pretty much anywhere. I have never bought bad gas, except once when I was in Arizona. I'm not suggesting that all gas in Arizona is bad, I'm only suggesting that the odds that he got a load of bad gas is within the bounds of reason. Octane booster is among the recovery options. It's also a valid test. If the octane booster makes the problem go away, then he can be reasonably sure there is no problem with his truck.

You might want to try some Chevron injector cleaner and some Auto Rx. which is available at autorx.com. That should clean up any carbon build up. Good Luck... =B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0= =B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0=B0

AS IN LIFE, IT'S THE JOURNEY, NOT THE DESTINATION THAT'S IMPORTANT.

Carbon built up in the combustion chamber glows red hot and causes ignition before the spark fires. If you have this, there are a few combustion chamber cleaning products that work well. Try Chevron Techron Concentrate, BG 44K, Red Line Fuel System Cleaner, or Seafoam.

"# I have seen the black bottle of Techron® Concentrate in Chevron service stations. What is the difference between Techron® and Techron® Concentrate?

"The principal difference between Techron® and Techron® Concentrate is additive concentration and rate of deposit clean-up. At the concentration present in Chevron gasolines, Techron® over many tankfuls will help clean up deposits on intake valves without contributing to combustion chamber deposits. So, over time, Chevron gasolines with Techron® are able to reduce or eliminate deposit-related hesitation and stumbling during acceleration caused by deposits. A bottle of Techron® Concentrate, when added to gasoline according to the label instructions, results in an additive concentration roughly 10 times stronger than the dose in our gasolines. This mega-dose of Techron® provides a much quicker clean up of intake valve deposits left by lower quality gasolines. In addition, the high concentration of Techron® reduces combustion chamber deposits, which can help reduce or eliminate deposit-related engine knock and run-on."

If you use the Seafoam in the process where you suck it slowly into the engine through a vacuum hose, do it at night. It'll smoke like mad, but it'll do a very good job.

Ken

Not exactlly. Will it can stay a little hot it is not red hot and the carbon increases the effective CR of engine and make it more prone to detenate with low octane fuel.

----------------- The SnoMan